A Printed Circuit Board (hereinafter termed “PCB”) is a vital element of virtually every electronic consumer device available today including, for example, appliances, toys, handheld devices, computers, and the like. Moreover, PCB technology has been implemented in critical applications such as, for example, medical, telecom, satellite, aerospace, and defense. In general, a PCB mechanically supports and electrically connects electronic components using conductive traces etched from copper sheets laminated into a non-conductive substrate.
There are presently four basic types of PCBs, which include rigid boards, flexible boards, rigid flex boards, and Microwave/RF boards. Moreover, PCBs may be single-sided, double-sided, and multilayer. Multilayer configurations include a plurality of layers of copper circuitry, which provides the electrical contact for proper functionality.
As applications have grown in sophistication, PCBs have followed suit. In order to maintain a smaller footprint, for example, PCBs may be stacked with adequate electrical connections existing between the stacked PCBs. PCBs are typically connected to other PCBs using an electrical connector. A wide variety of electrical connectors exist for the purpose of providing a highly reliable interconnect between PCBs. High reliability is critical, as any misconnection may cause a failure to occur within a system. Furthermore, a system failure on an end application may have catastrophic consequences, resulting in major financial losses and, more significantly, the loss of life.
Prior art PCB connector applications consist of the following example techniques. The following descriptions represent the more common generic approaches commercially available for highly reliable applications. However, the descriptions of the prior art do not include all generic approaches available. The following descriptions of the prior art are presented only to provide a perspective, which may help the reader to better understand and appreciate the inventor's unique connector and approach for connecting PCBs, which is presented herein.
Soldered Pin in Hole: This technology comprises installation of a pin within a plated through hole on a PCB. Once installed, the pin is soldered to provide both the mechanical and electrical connection between the connector and the PCB.
Double-Eye Compliant Pin: A compliant pin provides a press-fit connection between a printed circuit board plated through hole and the connector pin. The connection is made by pressing an over-sized pin into the drilled thru-hole of the PCB. The cross section of the pin is greater than the diameter of the hole and the compliant pin compresses and conforms to the barrel of the plated though hole within the PCB. The compliant pin forces against the hole wall to provide both the mechanical and electrical connection between the connector and the PCB.
A single compliant pin is used to make contact within one PCB, while a double compliant pin is used to connect two PCBs.
Pin/Socket: A pin, which can be un-insulated or insulated with a polymer material, may provide the interface between two PCBs. The plated thru-holes on the opposing PCBs contain a socket, which is press-fit into the holes and provide electrical contact to the PCB. The socket contains a bifurcated section which will provide electrical contact to the mating pin.
Compression: Compression mount style connectors are Z-Axis connector elements that are squeezed between two boards to achieve electrical contact. The connector is typically made up of a beryllium copper or silver filled elastomeric polymer on a rigid polymer carrier. The carrier interconnect is positioned between two components with matching connection footprints. The two components are compressed and fastened together.
Surface mount: A surface mount connector is soldered to exposed pads on the surface of a PCB. Two mating (opposite gender) connectors may each be placed on two horizontally opposing PCBs, such that when mated, will provide electrical connection between the two PCBs.
Conductive Ink: A method for establishing an electrical vertical Z-axis connection through the use of conductive pastes. Typical metal pastes that are commercially available create a permanent metal post within a PCB. During the melt stage of the paste, the composition undergoes a sintering process to permanently bond to the adjacent contact pads, thereby creating a contact. This approach may be implemented internally within a PCB to make vertical connections or externally for a PCB to PCB connection.
While each of the above described methodologies and techniques include inherent advantages and disadvantages, the development of such varied techniques demonstrates a need for a repeatable, efficient, and reliable process for constructing PCB interconnects, wherein the integrity of the conductive connections must be maintained. As such, there is a need for an efficient method for bonding PCBs while ensuring that the interconnects between the two individual PCBs are maintained.